High-order multipole radiation from quantum hall states in Dirac materials

作     者：Gullans, Michael J. Taylor, Jacob M. Imamoglu, Ataç Ghaemi, Pouyan Hafezi, Mohammad 

作者机构：Joint Quantum Institute NIST and University of Maryland College ParkMD20742 United States Joint Center for Quantum Information and Computer Science NIST and University of Maryland College ParkMD20742 United States Institute of Quantum Electronics ETH Zürich ZürichCH-8093 Switzerland Physics Department City College of the City University of New York New YorkNY10031 United States Physics Department Grad. Center City University of New York New YorkNY10031 United States Department of Electrical and Computer Engineering IREAP University of Maryland College ParkMD20742 United States 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2017年

核心收录：

主　　题：Solvents 

摘      要：We investigate the optical response of strongly disordered quantum Hall states in two-dimensional Dirac materials and find qualitatively different effects in the radiation properties of the bulk versus the edge. We show that the far-field radiation from the edge is characterized by large multipole moments ( 50) due to the efficient transfer of angular momentum from the electrons into the scattered light. The maximum multipole transition moment is a direct measure of the coherence length of the edge states. Accessing these multipole transitions would provide new tools for optical spectroscopy and control of quantum Hall edge states. On the other hand, the far-field radiation from the bulk appears as random dipole emission with spectral properties that vary with the local disorder potential. We determine the conditions under which this bulk radiation can be used to image the disorder landscape. Such optical measurements can probe sub-micron length scales over large areas and provide complementary information to scanning probe techniques. Spatially resolving this bulk radiation would serve as a novel probe of the percolation transition near half-filling. Copyright © 2017, The Authors. All rights reserved.